String instrument



0. E. WOLFF STRING INSTRUMENT July 3, 1951 3 Sheets-Sheet 1 Filed March19, 1948 w w\\\\ I I I m July 3, 1951 o. E. WOLFF 2,558,893

STRING INSTRUMENT Filed March 19, 1948 3 Sheets-Sheet 2 MZW July 3, 1951I o. E. WOLFF STRING INSTRUMENT Filed March 19, 1948 3 Sheets-Sheet 3lNVENTO R BY I Patented July 3, 1951 UNITED STATES PATENT OFFICE STRINGINSTRUMENT Otto E. Wolff, Cambridge, Mass.

Application March 19, 1948, Serial No. 15,920

23 Claims. 1

This invention relates to acoustic instruments, and more particularly tobowed string instruments.

One object of the present invention is to provide a novel bowed stringinstrument having a high level of tone quality and intensity wherein thevarious structural components which contribute to the tone of theinstrument are capable of accurate and uniform construction by massproduction processes.

A further object is to provide a bowed string instrument comprisingnovel motion-transmitting means interconnecting the bridge of theinstrument with the principal sound-producing member thereof.

Still another object of the invention is to provide a string instrumenthaving a cone speaker as its principal sound-producing member.

Still a further object is to provide a bowed string instrument havingone or more of the aforementioned novel features and so constructed thatone skilled in the playing of a string instrument of conventionalconstruction can play the corresponding instrument of the invention withequal facility and without special training.

A still further object is to provide a violin construction having novelbody-engaging elements permitting the same to be handled with easeduring use.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the product possessing the features,properties and the relation of components which are exemplified in thefollowing detailed disclosure, and the scope of the application of whichwill be indicated in the claims.

For a further understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying .drawings wherein:

Figure 1 is a side elevation of one form of a string instrument of thepresent invention, said instrument being of the violin type andembodying novel body-engaging means for facilitating the handlingthereof;

Fig. 2 is a top plan view of the instrument of I necting the bridge tothe sound-producing member of the instrument;

Fig. 5 is a fragmentary, sectional and somewhat diagrammatic view of anovel form of bridge-mounting means;

Fig. 7 is a fragmentary perspective view of the bridge mounting means ofFig. 6;

Fig. 8 is a transverse, fragmentary sectional view similar to Fig. 4 ofa modification of the novel instrument of the present invention whereina plurality of speaker units are used; and

Fig. 9 is a view in side elevation with parts broken away of theinstrument of Fig. 8.

There is provided, in accordance with the present invention, a bowedinstrument having a high level of tonal quality and tone intensity inwhichthe sound-producing parts are formed of standard engineeringmaterials and which is so constructed as to permit said parts to bemass-produced and assembled.

In the form illustrated by way of example in the drawings, theinstrument comprises a supporting member It which provides the principalsupports for the sound-producing elements while contributing onlynegligibly to the tone of the instrument, and is accordingly selectedprimarily for its strength, lightness and appearance, and may be formedof any suitable natural or synthetic material, for example, wood, metalor plastic.

Member IE3 is provided at one end thereof with a suitable peg box l2comprising a plurality of tuning pegs It and adjacent the other endthereof with a plurality of pins It, each said peg and, pin serving tomount a string I8 lengthwise of said member. Any other means may beemployed for holding string 18 and for adjusting the tautness thereof.For example, a conventional tail piece may be used in lieu of pins 16 tohold one end of each of the strings.

Connected to member I0 is a novel arrangement of body-engaging memberswhich permits the instrument to be easily held during use and in theform shown said arrangement comprises a chin-engaging member 20 which ispreferably rigidly secured to or integrally formed with support l0, saidchin-engaging member extending transversely from the end of said support(Fig. 2) and being provided with a chin-engaging surface 2| which may besuitably padded. Mounted beneath chin-engaging member 2% (Fig. 1) is achest-engaging plate 22, the mounting means therefor comprising, asillustrated, a rodlike element consisting of a V-shaped portion 24 and acurved portion 25. Chest-engaging plate 22 is slidably mounted fortransverse adjustment adjacent the vertex of said V-shaped portion, andone arm of said V-shaped portion is, in turn, slidably and rotatablymounted in a bracket 2'6 which is a part of or is secured to member lil.As a result of this mounting arrangement, the vertical and angularposition of chest-engaging element 22 with respect to chin-engagingsurface 2! may be readily adjusted to suit the convenience of the userof the instrument. Curved portion 25 of said rodlike member has acontour which adapts it for engaging the back of the players neckwhereby it becomes readily pos sible to adjust portion 25 and plate 22with respect to member 23 so that the instrument can be fully supportedin playing position only by the engagement of these elements with thebody of the player.

To pick off the vibrations of the strings and transmit the same to theprincipal sound-producing element of the instrument, novel means areprovided and in one form thereof said means comprise a bridge member 28(Figs. 1, 4 and 5) which has an arcuate upper surface that is notched toreceive the strings and which is located intermediate peg box I2 andpins [6 at a distance from pegs l4 approximately the same as thedistance normally separating the bridge from the pegs of a conventionalviolin. This construction is preferred since it provides a finger boardlike that of a violin and permits one trained to play a conventionalviolin to play the instrument of the present invention with equalfacility. Bridge 28 is preferably formed of a material such, forexample, as aluminum, or one of its alloys, a hard wood such as ebony,or a plastic such, for example, as the formaldehyde thermosettingresins, polymethacrylates, nylons and polystyrenes, or a phenoliclaminated material such as micarta, and is preferably provided withbroadened base portions 36 that facilitate the mounting thereof.

Means are provided for supporting bridge 28 to permit substantially freelateral movement of the latter in response to the vibration of strings[8, said mounting means constituting part of the motion transmittinglinkage whereby the lateral movement of the bridge is converted into avibration in a direction for efficiently actuating the principalsound-producing member of the instru ment. In the form shown, saidmounting means comprise a pair of hollow cylindrical members 32 and 34whose cylindrical surfaces engage and are supported by an upper surfaceportion of support l0 and engage and support the base portions 30 of thebridge. Each said cylindrical member may rest directly on the uppersurface of support [8, but in a preferred construction said support isprovided with a pair of inserts 36 whose upper surfaces act as bearingsurfaces for said cylinders. Inserts 36 may be adhered or otherwisefixed in a pair of grooves formed in the upper portion of support I!)just beneath the bridge. Each insert has its bearing surface polishedsmooth and any hard surfaced material may be used to form said insertssuch, for example, as ebony, Duralumin or a formaldehyde type resin.Strings l8, being under tension, apply a downward component of force tothe bridge which holds the latter in contact with members 32 and 34, andthis force in turn presses said members into firm contact with the uppersurfaces of inserts 36.

Lateral movement of bridge 28 tends to rotate cylinders 32 and 34, andthis rotation is converted to a substantially vertical motion by a lever38 connected to one of members 32, 34. Lever 38, in the form shown, isconnected to member 34 and may be formed of a single strip of metal bentto form a pair of arms 39 and a connecting portion 40 which issubstantially parallel to the axis of cylinder 34 (Fig. 5). Each of arms39 has the end thereof secured to an end of cylinder 34, and eachextends in a substantially radial direction with respect to the aXis ofcylinder 34, and also flares outwardly with respect to the other arm.Depending from connection portion 40, preferably from the centerthereof, is a strut or link 42, and rotation of cylinder 34 in responseto the bowing of one or more of the strings produces a substantiallyvertical vibration of link 42, Affixed to the end of link 42 as by beingintegrally formed therewith is the vertex of a conically shaped element44. Lever 38 may be formed of a strip of Phosphor bronze and cylinder 34of steel whereby said lever may be secured to said cylinder by beingsoldered thereto. Cylinder 32 may also be formed of steel or of anyother suitable metal such as Duralumin or a plastic. Link 42 and element44 ma be formed of Duralumin, in which case said link is secured toconnection portion ill by a suitable adhesive such as a nitrocellulosecement.

As the principal sound-producing unit of the instrument, there isprovided a cone speaker 46 which comprises a generally cone-shapeddiaphragm 48 whose upper end is secured as by adhesion to the lower edgeof element 44, a nitrocellulose adhesive being suitable for thispurpose. Diaphragm 48 is of any conventional construction, being formed,for example, of a stiff paper composition. The lower base end ofdiaphragm 48 is secured to a rim 5!] of the same general shape as saidbase, said rim being of a suitably rigid supporting material such aswood, plastic or metal, and being preferably attached as by anitrocellulose adhesive to the lower peripheral portion 52 of saiddiaphragm. Portion 52 is an integral extension of the diaphragm and isprovided with suitable corrugations or other extensible portions whichpermit of relatively free vibration of the diaphragm in response to thevertical vibration applied to the vertex portion thereof through link42. Cone speaker 46 may be of any conventional shape, but preferably thebase thereof is symmetrical about a longitudinal axis, and this axis ofsymmetry is located beneath and substantially parallel to support Ill.Preferably speaker 48 has an oval shape.

'I'o mount the cone speaker unit and to permit the foregoingVibration-transmitting mechanism which actuates said speaker unit to beoperatively connected thereto, support H) is provided with an aperture54 (Fig. 4) whose walls preferably flare outwardly from the upper to thelower end, the angle of flare being such as will adapt said aperture toreceive the upper vertex end of elements 44 and of the diaphragm 48without having the walls thereof contact the diaphragm or link 42, 44during operation thereof. To mount rim of said speaker unit, a pluralityof arms 56 (Fig. 3) extend downwardly and angularly from support l0,being secured to said support or, as shown, being integrally formedtherewith. Said arms are secured to rim 50 to support the same andprovide in conjunction with the recessed lower portion of support H] aspace for receiving diaphragm 48. One of said arms 56 serves to mountbracket 26.

In a preferred form of the violinlike construction describedhereinabove, cylinders 32 and 34 are formed of tubing having an outerdiameter of approximately .19 inch and the length of lever arm 38, i.e., the distance from the center of cylinder 34 to the verticallongitudinal axis of link 42, is approximately .44 inch. The effectivelever arm ratio of the linkage which transmits the motion of the bridge28 to the diaphragm I8 is thus approximately 2.4, so that the amplitudeof a vibration of the bridge is magnified roughly 2.4 times. For optimumperformance, this lever arm ratio is greater than 1 and is preferablybetween 2 and 3.

Although the shape of diaphragm 48, as shown, is that of a segment of acone generated by a straight line having one end fixed and the othermoving-in an oval path, it is within the scope of the invention to usediaphragms of. other shapes as, for example, those generated'by a curvedinstead of a straight line, orby a linemoving in a circular or apolygonal instead-of an ova-l' ath. It is to be understood that the termcone-shaped diaphragm as used herein-includes diaphragms of thesevarious shapes.

The instrument may be muted by changing the position of cylindricalmember 32, so that its axis instead of being parallel to the axis ofcylinder 34 and perpendicular to the lateral movement of bridge 28,becomes inclined to the axis of said cylinder 34. The more closely thecylinder axis approaches parallelism with the direction of movement'ofbridge 28, the greater isthe muting effect.

A novel modification of the bridge means ofthe invention, as well as ofthe mechanism for transmitting the lateral vibration of said bridge to asound-producing speaker unit to actuate the same, are shown in Figs. 6and 7. As shown, said bridge means comprise a suspending member 60' inthe form of an inverted U whose arms are secured to the main supportingmember 62 of the instrument as by screws 63 and whose central curvedportion extends transversely of the instrument at a point which is abovethe desired location for the bridge. A plurality of bores pref erablyequal in number to the number of strings and located approximately abovethe strings are provided in the curved portion of member 69, each borebeing threaded and having threaded therein a set screw 64 and each setscrew having an axial passage therein. Arcuate bridge member 68 issuspended by member 60 by means of a suitable filament suspending means,for example, a single filament 'H] of metal wire or nylon which isknotted at one end to prevent the same from passing through the passagein one of the end set screws and which has the free end thereofextending through said passagein said set screw to and through a recess12 in bridge member 68 and back again through the passage in said setscrew. The filament extends down again in a loop through each successivepassage of the other set screws and is looped each time through a recess12 in the bridge member. The free end of the filament is then knotted.In this manner, the filament T is caused to extend througheach of theset screws to suspend the bridge member 68 at four points. Each of thefour recesses 12 in the bridge member through which the filament H3 islooped may have one of the strings 13 of the instrument threadedtherethrough to support the same. As a result of this mounting, bridgemember 68 is freely suspended for arcuate lateral movement in responseto the bowing of each of the strings. The strings apply a downward com-6. ponent to the bridge member, maintaining filament 10 taut. To effectslight adjustments in the position of the bridge member, one or both endset screws 64 may have its position adjusted in support 6|].

To transmit the lateral movement of bridge member 68 to a link 14 whichis connected to the vertex of a suitable cone speaker unit 16 foractuating the same, there is provided a lever 78. Lever lt may be formedof a suitable metal such, for example, as spring steel, and may beV-shaped with the vertexthereof secured as, for example, by means of anadhesive to link 14. The ends of the arms thereof are held under tensionbetween bridge member 68 and the upper surface of support 62, and arepreferably provided with angularly extending portions ?8a. which fitinto a pair of grooves l! and 79. Groove 19 is provided in the loweredge of bridge 68 adjacent on endthereof. Groove 11 may be formed in theupper surface of support 62, but as shown is formed in the head of ametallic insert 8| which is rigidly held as by a force fit in saidsupport 62. Lateral movement of bridge 63 causes lever TBto pivot aboutthe vertex of groove TI and produces a substantially vertical movementof link 14 operating the diaphragm of speaker unit 16. It is to beunderstood that the mounting and construction of the speaker unit- !6 islike that of speaker unit it of the embodiment of Figs. 1 to 5.

By providing a bridge suspension of this type, it becomes possible touse bridge members of minimum weight and mass, thereby reducing inertiaeffects to a minimum.

In another modification of the invention, a plurality of bridges,motion-transmitting linkages and speaker units may be employed, and onesuch modification is shown in Figs. 8 and 9 wherein two cone speakers 89and 82 are mounted in spaced, substantially concentric relationship on asupporting member 84. Each of speakers and 82 has the diaphragm thereofactuated by'a separate link 86-and 88, respectively. Speaker unit 89whose diaphragm is the outer diaphragm is provided adjacent its vertexwith a suitable aperture 98 through which link 88-extends. Link 88 isshown substantially parallel to link 86 and adapted for vibration in adirection substantially parallel to the vibration direction of link- 88,but it is to be understood that link 88 mayextend-at an angle to link 86and may be adapted to vibrate in a direction substantially parallel toits axis.

Links 86 and 88, inturn, are connected to the ends of levers 92 and 94,respectively, said levers being of the same general construction as, forexample, lever 38 of the embodiment of Figs. 1- through 5, the otherends of each of said levers 92 and 9H being connected to cylindricalmembers and 93, respectively, which cylindrical members in turn supportthe base portions of a pair of bridges 69 and 182, respectively. Bridge[30' is provided with a pair of notches to support two of the stringsin! an-d'bridge 562 is provided with two more notches to support theother two strings ii]! of the instrument. The inner adjacent ends ofsaid bridge portions have their lower surfaces I94 and H35,respectively, elevated a substantial distance above the surfaces thereofwhich engage cylinders 95 and 98 and these elevated surfaces HM- and 156rest on cylindrical members we and I [0, respectively, which cylindricalmembers provide a second support for each bridge. These cylindricalmembers rest on the upper surface of a Supporting platform H2 whichextends over levers 92 and 94 and rigidly secured to support ing member84. Cylinders 96 and 98 ride on the bottom wall of said groove andlevers 92 and 94 pivot between the side walls thereof.

In the form shown, inner diaphragm 82a of cone speaker unit 82 is thelarger and is preferably provided with a plurality of perforations H4 inorder to minimize the impedance efiects of its presence upon diaphragm80a of speaker unit 80. To mount speaker unit 82, support 84 is providedwith a pair of depending arms H6 whose ends engage and are secured, asby adhesion, to rim 82b of said speaker unit 82. Each of arms HE ispreferably provided adjacent its upper end with an inward projectionwhich provides a shoulder H8 to which the rim 8% of speaker unit 80 isaffixed.

Preferred results are obtained by having smaller cone 80 actuated by thebridge which supports the E and A strings and by having unit 82 actuatedby the bridge which supports the D and G strings, and this preferredarrangement is illustrated in the drawings. Similarly, it has beendetermined that most satisfactory results with the foregoing arrangementare obtained if lever 94 which actuates diaphragm 86a has a lever ratioless than the lever ratio of lever 92 which actuates the larger andheavier diaphragm 82a. Preferably, lever 94 has a lever ratio betweenone and two, and lever 92 has a lever ratio over two.

Although in the above-described embodiment there are shown two bridgesand two speaker units, and each bridge supports two of the strings, itwill be readily appreciated that one of said bridges may support but onestring while the other supports three or" the strings, or that there maybe provided a greater number of bridges and speaker units, for example,a bridge and the speaker unit for each of the strings.

It will be noted that in each of the foregoing embodiments of theinvention the bridge member is mounted for relatively free lateralmovement and its lateral movement is not appreciably inhibited by thelever arm linkage which connects said bridge member to the diaphragm ofthe speaker unit. In each instance the lever arm is capable of a rockingmovement relative to the bridge member so that the vibration of thelever arm is a direct function of the magnitude of lateral movement ofthe strings which causes the lateral displacement of the bridge member.

This results in a high fidelity of tone reproduction.

Although the present invention has been illustrated and describedhereinabove as embodied in a bowed string instrument of the violin type,.1

it will now be apparent to those skilled in the art that it may beembodied in other types of string instruments, e. g., instruments likethe viola, the cello and the bass violin.

Since certain changes may be made in the above product without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. In a string instrument comprising supporting means, a plurality ofstrings mounted tautly on said supporting means, and a bridge memberengaging at least one of said strings intermediate the ends of the tautportion thereof, the combination therewith of sound-producing meanscomprising a cone-shaped diaphragm mounted on said supporting means withits apex portion adjacent said bridge member and with its axissubstantially perpendicular to the longitudinal axis of said supportingmeans, and means for mounting said bridge member for lateral movement inresponse to the bowing of said string and for transmitting said lateralmovement to said diaphragm to actuate the latter, said lastnamed meanscomprising a lever free to move relative to said bridge member and alink extending substantially perpendicularly to the lateral movement ofsaid bridge member connecting said lever to the apex of said cone-shapeddiaphragm, lateral movement of said bridge member causing angularmovement of said lever and movement of said link along its longitudinalaxis to actuate said diaphragm.

2. In a string instrument comprising supporting means, a plurality ofstrings mounted tautly on said supporting means, and a bridge memberengaging at least one of said strings intermediate the ends of the tautportion thereof, the combination therewith of sound-producing meanscomprising a cone-shaped diaphragm mounted on said supporting means withits apex portion adjacent said bridge member, and means for mountingsaid bridge member and for transmitting the movement thereof to saiddiaphragm, said last-named means comprising a plurality of laterallyspaced supports for said bridge member arranged to permit lateralvibration of said bridge member in response to the bowing of said stringand including a lever so connected to said bridge member and to saiddiaphragm as to be moved angularly relative to said bridge member inresponse to lateral vibration of the latter without appreciablyrestricting said lateral vibration, said lever actuating said diaphragmwhen moved angularly, said supporting means having no appreciablesound-producing effect in response to the vibration of said string, andsaid coneshaped diaphragm constituting the sole effectivesound-producing element of said instrument for converting the vibrationof said string to sound.

3. In a string instrument comprising supporting means, a plurality ofstrings mounted tautly on said supporting means, and a bridge memberengaging at least one of said strings intermediate the ends of the tautportion thereof, the combination therewith of sound-producing meanscomprising a cone-shaped diaphragm mounted on said supporting means withthe apex portion thereof adjacent said bridge member, and means formounting said bridge member and for transmitting the movement thereof tosaid diaphragm, said last-named means comprising a plurality oflaterally spaced supports for said bridge member arranged to permitlateral vibration of said bridge member in response to the bowing ofsaid string and including a lever so connected to said bridge member andto the apex portion of said diaphragm as to be moved angularly relativeto said bridge member in response to lateral vibration of the latterwithout appreciably restricting said lateral vibration, said leveractuating said diaphragm when moved angularly.

4. In a string instrument comprising supporting means, a plurality ofstrings mounted tautly on said supporting means, and a bridge memberengaging at least one of said strings intermediate the ends of the tautportion thereof, the combination therewith of sound-producing meanscomprising a cone-shaped diaphragm having a plane of symmetry andmounted with the plane of symmetry thereof located in substantialcoincidence with the longitudinal axis of said supporting means and withthe apex portion thereof adjacent said bridge member, and means formounting said bridge member and for transmitting the movement thereof tosaid diaphragm, said last-named means comprising a plurality oflaterally spaced supports for said bridge member arranged to permitlateral vibration of said bridge member in response to the bowing ofsaid string and including a lever so connected to said bridge member andto the apex portion of said diaphragm as to be moved angularly relativeto said bridge member in response to the lateral vibration of the latterwithout appreciably restricting said lateral vibration, said leveractuating said diaphragm when moved angularly.

5. A string instrument comprising, in combination, a main supportextending longitudinally of the instrument, a plurality of strings,means mounted on said support and engaging said strings to hold the sametaut lengthwise of said L support, a bridge member engaging at least oneof said strings intermediate the ends of the taut portion thereof,sound-producing means comprising a cone-shaped diaphragm having an apexportion adjacent to said bridge member and a base portion, a rim membersecured to said base portion, means comprising a pair of dependingelements for securing said rim.member to said main support, and meansfor supporting said bridge member and for transmitting the movementthereof to said diaphragm to actuate the latter, said last-named meanscomprising a plurality of laterally spaced supports for said bridgemember arranged to permit lateral vibration of said bridge member inresponse to the bowing of said string and including a lever so connectedto said bridge member and to the apex portion of said diaphragm as to bemoved angularly relative to said bridge member in response to thelateral vibration of the latter without appreciably restricting saidlateral vibration, said lever actuating said diaphragm when movedangularly, said main support having no appreciable sound-producingefiect in response to the vibration of said string, and said coneshapeddiaphragm constituting the sole effective sound-producin element of saidinstrument for converting the vibration of said stringto-sound.

6. A string instrument comprising, in combination, supporting means, aplurality of strings mounted tautly on said supporting means, a bridgemember engaging at least one of said strings interm diate the ends ofthe taut portion thereof, soundroducing means comprising a diaphragm,and mean for mounting said bridge member for lateral movement inresponse to the bowing of said string and for transmitting said lateralmovement to said diaphragm to actuate the latter,.said last-named meanscomprising a V-shaped lever member havin the end of onearm of the V inengagement with said bridge member, the end of the other arm of the V inengagement with said supportin means and the apex portion of the -Vconnected to said diaphragm, lateral movement of said bridgemember-causin a corresponding movement of said lever portion inengagement therewith and producing .a rockin movement of said leverabout the portion thereof engaging said supporting means whereby avibration actuating said diaphragm is obtained.

7. A string instrument comprising, in combination, a main supportextendin longitudinally of the instrument, a plurality of strings, meansmounted on said support and engaging said strings to hold the same tautlengthwiseof said support, abridge member engaging at leastone of saidstrings intermediate the ends of the taut portion thereof,sound-producing means comprising a cone-shaped-diaphragm, and means formounting said bridge member for lateral movement in response to thebowin of said string and for transmitting said lateral movement to saiddiaphragm to actuate the latter, said last-named meanscomprising aV-shaped leverhaving the end of one arm of the V in engagement with saidbridge member, the end of the other arm of the V in engagement with saidmain support and the apex portion of the V connected to said diaphragm,lateral move ment of said bridge member causing a corresponding movementof said lever portion inengagement therewith and producing a rockingmovement of said lever about the portion thereof engaging said mainsupport whereby -a vibration actuating said diaphragm is obtained.

3. A string instrument comprising, in combination, a main supportextending longitudinally of the instrument, a plurality of strings,means mounted on said support and engaging said strings to hold the sametaut lengthwise ofsaid support, a bridge member engagin at least one ofsaid string intermediate the ends of the taut portion thereof,sound-producing means comprising a coneshaped diaphragm having an apexportion adjacent to said bridge member and a base portion, a rim membersecured to said base portion, means for securing said rim member to saidmain support, and means for mounting said bridge member for lateralmovement in response to the bowing of said string and for transmittingsaid lateral movement to said diaphragm to actuate the latter, saidlastnamed means comprising a V-shaped lever member having the end of onearm of the V in engagement with said bridge member, the end of the otherarm of the V in engagement with said main support and the apex portionof the V connected to said apex portion of said diaphragm, lateralmovement of said bridge member causing a corresponding movement of saidlever portion in engagement therewith and producing a rocking movementof said lever about the portion'thereof engaging said main supportwhereby a vibration actuating said diaphragm is obtained.

9. A strin instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid strings intermediate the ends of the taut portion thereof, sound-.producing means comprising a diaphragm, and

means for mounting said bridge member for lateral movement in responseto the bowing of said string and for transmitting said lateral movementto said diaphragm to actuate the latter, said last-named meanscomprising a plurality of separate members supporting said bridgemember, one of said supporting members being cylindrical, saidcylindrical member being only in frictional engagement with said bridgemember and bein rotated by the lateral movement of said bridge member,and an arm connected to said cylindrical member to form a levertherewith and adapted to rock in response to the rotary movement of saidcylindrical member, said arm being connectedto said diaphragm.

10. A strin instrument comprising, in combination, a main supportextending longitudinally of the instrument, ,9, plurality of strings,means i1 mounted on said support and engaging said strings to hold thesame taut lengthwise of said support, a bridge member engaging at leastone of said strings intermediate the ends of the taut portion thereof,sound-producing means comprising a cone-shaped diaphragm, and means formounting said bridge member for lateral movement in response to thebowing of said strin and for transmitting said lateral movement to saiddiaphragm to actuate the latter,

said last-named means comprising a plurality of separate memberssupporting said bridge member, one of said members being cylindrical,said cylindrical member being only in frictional engagement with saidbridge member and being rotated by the lateral movement of said bridgemember, and an arm connected to said cylindrical member to form a levertherewith and adapted to rock in response to the rotary movement of saidcylindrical member, said arm being connected to said diaphragm.

11. A string instrument comprising, in combination, a main supportextending longitudinally of the instrument, a plurality of strings,means mounted on said support and engaging said strings to hold the sametaut lengthwise of said support, a bridge member engaging at least oneof said strings intermediate the ends of the taut portion thereof,sound-producing means comprising a cone-shaped diaphragm having an apexportion adjacent to said bridge member and a base portion, a rim membersecured to said base portion, means for securing said rim member to saidmain support, and means for mounting said bridge member for lateralmovement in response to the bowing of said string and for transmittingsaid lateral movement to said diaphragm to actuate the latter, saidlast-named means comprising a plurality of cylindrical memberssupporting said bridge member and an arm connected to one of saidcylindrical members to form a lever therewith and adapted to rock inresponse to the rotary movement of said cylindrical member, said armbeing connected to said apex portion of said diaphragm.

12. A string instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid strings intermediate the ends of the taut portion thereof,sound-producing means comprising a diaphragm, and means for mountingsaid bridge member for lateral movement in response to the bowing ofsaid string and for transmitting said lateral movement to said diaphragmto actuate the latter, said last-named means comprising a lever having aportion thereof in engagement with said bridge member, another portionthereof in engagement with said main support, and a third portionthereof connected to said diaphragm, lateral movement of said bridgemember causing a corresponding movement of said lever portion inengagement therewith and producing a rocking movement of said leverabout the portion thereof engaging said main support whereby a vibrationactuatin said diaphragm is obtained, said lever having an eiiectivelever arm ratio in excess of 1, thereby amplifying the motiontransmitted from said bridge member to said diaphragm.

13. A string instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge.

member engaging at least one of said strings intermediate the ends ofthe taut portion thereof, sound-producing mean comprising a diaphragm,and means for mounting said bridge member for lateral movement inresponse to the bowing of said string and for transmitting said lateralmovement to said diaphragm to actuate the latter, said last-named meanscomprising a lever having a portion thereof in engagement with saidbridge member, another portion thereof in engagement with said mainsupport, and a third portion thereof connected to said diaphragm,lateral movement of said bridge member causing a corresponding movementof said lever portion in engagement therewith and producing a rockingmovement of said lever about the portion thereof engaging said mainsupport whereby a vibration actuating said diaphragm is obtained, saidlever amplifying the motion of said bridge member two to three times.

14. A string instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid strings intermediate the ends of the taut portion thereof,sound-producing means comprising a coneshaped diaphragm, and means formounting said bridge member for lateral movement in response to thebowing of said string and for transmitting said lateral movement to saiddiaphragm to actuate the latter, said diaphragm constituting the soleeffective means for converting the vibration of said string to sound,said mean support having no appreciable sound-producing eiTect inresponse to the vibration of said string.

15. A string instrument comprising, in combination a main supportextending longitudinally of the instrument, a plurality of strings,means mounted on said support and engaging said strings to hold the sametaut, a bridge member engaging at least one of said strings intermediatethe ends of the taut portion thereof, soundproducing mean comprising acone-shaped diaphragm, and means for mounting said bridge member forlateral movement in response to the bowing of said string and fortransmitting said lateral movement to said diaphragm to actuate thelatter, said diaphragm having a plane of symmetry and being mounted onsaid support with its plane of symmetry in substantial coincidence withthe longitudinal axis of said support.

16. A string instrument comprising, in combination, a main supportextending longitudinally of the instrument, a plurality of strings,means mounted on said support and engaging said strings to hold the sametaut, a bridge member engaging at least one of said strings intermediatethe ends of the taut portion thereof, soundproducing means comprising acone-shaped diaphragm, and means for mounting said bridge member forlateral movement in response to the bowing of said string and fortransmitting said lateral movement to said diaphragm to actuate thelatter, said diaphragm being oval shaped and being mounted on saidsupport with it axis of symmetry located beneath and substantiallyparallel to said support.

17. In a hand-held bowed string instrument of the violin type, meanssecured to said instrument and capable of engaging the body of theinstrumentalist to facilitate the handling and playing of theinstrument, said means comprising a chin-engaging member, achest-engaging member located beneath said chin-engaging member, and adownwardly and rearwardly extending element including an arcuate portionso located relative to said chin-engagin and chestengaging members as tofit behind the neck of the instrumentalist, said chest-engaging memberbeing mounted on said element below said chinengaging member.

18. In a hand-held bowed string instrument of the violin type, meanssecured to said instrument and capable of engaging the body of theinstrumentalist to facilitate the handlin and playing of the instrument,said mean comprising a chin-engaging member, a rodlike member extendingrearwardly and downwardly relative to said chin-engaging member, saidrodlike member comprisin a curved portion to the rear of saidchin-engaging member for engaging the neck of the instrumentalist and achest-engaging plate mounted on said rodlike member beneath saidchin-engaging member.

19. A strin instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid strings intermediate the ends of the taut portions thereof,sound-producing means comprising a diaphragm, means for supporting saidbridge member for movement in response to the bowing of said string,said means comprising a filamentsupporting member secured to said mainsupport and filament means comprising at least a single filament mountedon said filament-supporting member and connected to said bridge memberto suspend the same for relatively free lateral movement with respect tosaid filament-supporting member, and means for transmittin the movementof said bridge member to said diaphragm to actuate the latter.

20. A string instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid strings intermediate the ends of the taut portion thereof,sound-producing means comprising a diaphragm, means for supporting saidbridge member for movement in response to the bowing of said string,means for supporting said bridge member for movement in response to thebowing of said string, said means comprisin a filamentsupporting membersecured to said main support with a, portion thereof located above saidbridge member and filament means comprising at least a single filamentmounted on said portion of said filament-supporting member and connectedto said bridge member to suspend the same for relatively free lateralmovement with respect to said filament-supporting member, and means fortransmitting the movement of said bridge member to said diaphragm toactuate the latter.

21. A string instrument comprising, in combination, a main support, aplurality of strings, means mounted on said support and engaging saidstrings to hold the same taut, a bridge member engaging at least one ofsaid string intermediate the ends of the taut portion thereof,sound-producing means comprising a diaphragm, means for supporting saidbridge member for movement in response to the bowing of said string,means for supporting said bridge member for movement in response to thebowing of said string, said means comprising a filament-supportingmember secured to said main support with a portion thereof located abovesaid bridge member and filament means comprising at least a singlefilament mounted on said portion of said filament-supporting member andconnected to said bridge member to suspend the same for relatively freelateral movement with respect to said filament-supporting member, saidfilament extending from said supporting member in a plurality of spacedloops, each said loop connecting with a different portion of said bridgemember, and means for transmitting the movement of said bridge member tosaid diaphragm to actuate the latter.

22. A string instrument as recited in claim 6 wherein a second bridgemember engage another one of said strings, a second diaphragm is mountedon said supporting means, and means are provided for comiecting saidsecond bridge member to said second diaphragm whereby the lateralmovement of said other string is caused to actuate said seconddiaphragm.

23. A string instrument as recited in claim 11 wherein a second bridgemember engages another one of said strings, a second diaphragm ismounted on said supporting means, and means are provided for connectingsaid second bridge member to said second diaphragm whereby the lateralmovement of said other strin is caused to actuate said second diaphragm.

OTTO E. WOLFF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 451,744 Albert May 5, 1891906,407 Gillespie Dec. 8, 1908 1,315,015 Boyle Sept. 2, 1919 1,431,773Bond Oct. 10, 1922 1,455,916 Kalaf May 22, 1923 1,643,044 Askelson Sept.20, 1927 1,762,617 Dopyera June 10, 1930 2,139,099 Robertson Dec. 6,1938 FOREIGN PATENTS Number Country Date 43,334 Switzerland May 11, 1908

